1. Technical Field
The present invention relates to an image recognition technology performing a generic object recognition, and particularly to a pyramid matching technology.
2. Background Art
In recent years, generic object recognition methods using the Spatial Pyramid Matching (SPM) (see Non-Patent Literature 1) have been proposed. In the SPM, a histogram representing the feature of an input image is computed. This computation includes hierarchical segmentation of the input image, which includes segmenting the input image into a plurality of sub-regions and segmenting each sub-region further into a plurality of sub-regions. Histograms are then computed for the respective sub-regions in each pyramid level, and the histograms are concatenated to generate a histogram representing the feature of the input image.
This enables the histogram representing the feature of the input image to reflect the geometrical positional relationship between the sub-regions formed by repeatedly segmenting the input image, thereby improving the accuracy of the generic object recognition.